From: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp
commit b8ebf250997c5fb253582f42bfe98673801ebebd upstream.
syzbot is reporting uninitialized value at iforce_init_device() [1], for commit 6ac0aec6b0a6 ("Input: iforce - allow callers supply data buffer when fetching device IDs") is checking that valid length is shorter than bytes to read. Since iforce_get_id_packet() stores valid length when returning 0, the caller needs to check that valid length is longer than or equals to bytes to read.
Reported-by: syzbot syzbot+4dd880c1184280378821@syzkaller.appspotmail.com Signed-off-by: Tetsuo Handa penguin-kernel@I-love.SAKURA.ne.jp Fixes: 6ac0aec6b0a6 ("Input: iforce - allow callers supply data buffer when fetching device IDs") Link: https://lore.kernel.org/r/531fb432-7396-ad37-ecba-3e42e7f56d5c@I-love.SAKURA... Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov dmitry.torokhov@gmail.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/input/joystick/iforce/iforce-main.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)
--- a/drivers/input/joystick/iforce/iforce-main.c +++ b/drivers/input/joystick/iforce/iforce-main.c @@ -273,22 +273,22 @@ int iforce_init_device(struct device *pa * Get device info. */
- if (!iforce_get_id_packet(iforce, 'M', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'M', buf, &len) && len >= 3) input_dev->id.vendor = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet M\n");
- if (!iforce_get_id_packet(iforce, 'P', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'P', buf, &len) && len >= 3) input_dev->id.product = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet P\n");
- if (!iforce_get_id_packet(iforce, 'B', buf, &len) || len < 3) + if (!iforce_get_id_packet(iforce, 'B', buf, &len) && len >= 3) iforce->device_memory.end = get_unaligned_le16(buf + 1); else dev_warn(&iforce->dev->dev, "Device does not respond to id packet B\n");
- if (!iforce_get_id_packet(iforce, 'N', buf, &len) || len < 2) + if (!iforce_get_id_packet(iforce, 'N', buf, &len) && len >= 2) ff_effects = buf[1]; else dev_warn(&iforce->dev->dev, "Device does not respond to id packet N\n");